Add is_fedora and exit_distro_not_supported functions

Between is_fedora, is_ubuntu and is_suse, we can make the code a bit
simpler to read. We also use exit_distro_not_supported to identify
places where we need implementation details for new distros.

As "/sbin/service --skip-redirect" is Fedora-specific, guard this with a
is_fedora test too.

Change-Id: Ic77c0697ed9be0dbb5df8e73da93463e76025f0c
diff --git a/lib/cinder b/lib/cinder
index 9b9d50d..a43f0a1 100644
--- a/lib/cinder
+++ b/lib/cinder
@@ -195,8 +195,8 @@
         mkdir -p $CINDER_STATE_PATH/volumes
 
         if sudo vgs $VOLUME_GROUP; then
-            if [[ "$os_PACKAGE" = "rpm" ]]; then
-                # RPM doesn't start the service
+            if is_fedora || is_suse; then
+                # service is not started by default
                 start_service tgtd
             fi
 
@@ -245,9 +245,15 @@
             # do it in two steps
             sudo stop tgt || true
             sudo start tgt
-        else
+        elif is_fedora; then
             # bypass redirection to systemctl during restart
             sudo /sbin/service --skip-redirect tgtd restart
+        elif is_suse; then
+            restart_service tgtd
+        else
+            # note for other distros: unstack.sh also uses the tgt/tgtd service
+            # name, and would need to be adjusted too
+            exit_distro_not_supported "restarting tgt"
         fi
     fi
 
diff --git a/lib/databases/mysql b/lib/databases/mysql
index 60ea143..68e9adc 100644
--- a/lib/databases/mysql
+++ b/lib/databases/mysql
@@ -23,22 +23,28 @@
     if is_ubuntu; then
         MY_CONF=/etc/mysql/my.cnf
         MYSQL=mysql
-    else
+    elif is_fedora; then
         MY_CONF=/etc/my.cnf
-        if is_suse; then
-            MYSQL=mysql
-        else
-            MYSQL=mysqld
-        fi
+        MYSQL=mysqld
+    elif is_suse; then
+        MY_CONF=/etc/my.cnf
+        MYSQL=mysql
+    else
+        exit_distro_not_supported "mysql configuration"
     fi
 
     # Start mysql-server
-    if [[ "$os_PACKAGE" = "rpm" ]]; then
-        # RPM doesn't start the service
+    if is_fedora || is_suse; then
+        # service is not started by default
         start_service $MYSQL
-        # Set the root password - only works the first time
+    fi
+
+    # Set the root password - only works the first time. For Ubuntu, we already
+    # did that with debconf before installing the package.
+    if ! is_ubuntu; then
         sudo mysqladmin -u root password $DATABASE_PASSWORD || true
     fi
+
     # Update the DB to give user ‘$DATABASE_USER’@’%’ full control of the all databases:
     sudo mysql -uroot -p$DATABASE_PASSWORD -h127.0.0.1 -e "GRANT ALL PRIVILEGES ON *.* TO '$DATABASE_USER'@'%' identified by '$DATABASE_PASSWORD';"
 
@@ -84,10 +90,12 @@
         chmod 0600 $HOME/.my.cnf
     fi
     # Install mysql-server
-    if is_suse; then
+    if is_ubuntu || is_fedora; then
+        install_package mysql-server
+    elif is_suse; then
         install_package mysql-community-server
     else
-        install_package mysql-server
+        exit_distro_not_supported "mysql installation"
     fi
 }
 
diff --git a/lib/databases/postgresql b/lib/databases/postgresql
index d9c2f00..20ade85 100644
--- a/lib/databases/postgresql
+++ b/lib/databases/postgresql
@@ -20,7 +20,7 @@
 
 function configure_database_postgresql {
     echo_summary "Configuring and starting PostgreSQL"
-    if [[ "$os_PACKAGE" = "rpm" ]]; then
+    if is_fedora || is_suse; then
         PG_HBA=/var/lib/pgsql/data/pg_hba.conf
         PG_CONF=/var/lib/pgsql/data/postgresql.conf
         sudo [ -e $PG_HBA ] || sudo postgresql-setup initdb
@@ -53,10 +53,12 @@
     else
         sed -i "s/:root:\w\+/:root:$DATABASE_PASSWORD/" $PGPASS
     fi
-    if [[ "$os_PACKAGE" = "rpm" ]]; then
+    if is_ubuntu; then
+        install_package postgresql
+    elif is_fedora || is_suse; then
         install_package postgresql-server
     else
-        install_package postgresql
+        exit_distro_not_supported "postgresql installation"
     fi
 }
 
diff --git a/lib/horizon b/lib/horizon
index 7321cbc..68337ab 100644
--- a/lib/horizon
+++ b/lib/horizon
@@ -81,19 +81,18 @@
         sudo a2ensite horizon
         # WSGI doesn't enable by default, enable it
         sudo a2enmod wsgi
+    elif is_fedora; then
+        APACHE_NAME=httpd
+        APACHE_CONF=conf.d/horizon.conf
+        sudo sed '/^Listen/s/^.*$/Listen 0.0.0.0:80/' -i /etc/httpd/conf/httpd.conf
+    elif is_suse; then
+        APACHE_NAME=apache2
+        APACHE_CONF=vhosts.d/horizon.conf
+        # Append wsgi to the list of modules to load
+        grep -q "^APACHE_MODULES=.*wsgi" /etc/sysconfig/apache2 ||
+            sudo sed '/^APACHE_MODULES=/s/^\(.*\)"$/\1 wsgi"/' -i /etc/sysconfig/apache2
     else
-        # Install httpd, which is NOPRIME'd
-        if is_suse; then
-            APACHE_NAME=apache2
-            APACHE_CONF=vhosts.d/horizon.conf
-            # Append wsgi to the list of modules to load
-            grep -q "^APACHE_MODULES=.*wsgi" /etc/sysconfig/apache2 ||
-                sudo sed '/^APACHE_MODULES=/s/^\(.*\)"$/\1 wsgi"/' -i /etc/sysconfig/apache2
-        else
-            APACHE_NAME=httpd
-            APACHE_CONF=conf.d/horizon.conf
-            sudo sed '/^Listen/s/^.*$/Listen 0.0.0.0:80/' -i /etc/httpd/conf/httpd.conf
-        fi
+        exit_distro_not_supported "apache configuration"
     fi
 
     # Configure apache to run horizon
@@ -113,11 +112,13 @@
     if is_ubuntu; then
         # Install apache2, which is NOPRIME'd
         install_package apache2 libapache2-mod-wsgi
+    elif is_fedora; then
+        sudo rm -f /etc/httpd/conf.d/000-*
+        install_package httpd mod_wsgi
     elif is_suse; then
         install_package apache2 apache2-mod_wsgi
     else
-        sudo rm -f /etc/httpd/conf.d/000-*
-        install_package httpd mod_wsgi
+        exit_distro_not_supported "apache installation"
     fi
 
     # NOTE(sdague) quantal changed the name of the node binary
diff --git a/lib/nova b/lib/nova
index 3a4d34d..8272ef0 100644
--- a/lib/nova
+++ b/lib/nova
@@ -394,11 +394,13 @@
 function install_nova() {
     if is_service_enabled n-cpu; then
         if is_ubuntu; then
-            LIBVIRT_PKG_NAME=libvirt-bin
+            install_package libvirt-bin
+        elif is_fedora || is_suse; then
+            install_package libvirt
         else
-            LIBVIRT_PKG_NAME=libvirt
+            exit_distro_not_supported "libvirt installation"
         fi
-        install_package $LIBVIRT_PKG_NAME
+
         # Install and configure **LXC** if specified.  LXC is another approach to
         # splitting a system into many smaller parts.  LXC uses cgroups and chroot
         # to simulate multiple systems.